The invention relates to an electrically driven axle of a two-track vehicle having drive shafts which are assigned to the wheels and an axle carrier with a plurality of wheel-guiding control members fastened thereto. With respect to the state of the art, reference is made, for example, to German Patent document DE 44 21 425 C1.
Two-track vehicles, particularly passenger cars, which are driven either solely, or as an alternative to an internal-combustion engine, by an electric motor, are becoming increasingly important. For this purpose, investigations are taking place for simple axle concepts which not only simplify the manufacturing process of the vehicle but, in particular, also make it possible in a simple manner to optionally equip a vehicle body with different axle concepts, of which, for example, only one permits an electric vehicle drive while another axle concept may be provided for a different power source.
It is an object of the invention to provide a unique axle concept for an electric drive of a vehicle.
According to the present invention, an electrically driven axle of a two-track vehicle is provided with drive shafts assigned to the wheels and an axle carrier having a plurality of wheel-guiding control members fastened thereto. At least one electric motor is fastened to the axle carrier. Furthermore, a housing containing elements for providing electric power for the electric motor is fastened to the axle carrier or forms a component of the axle carrier in the shape of a base body.
According to the invention, not only one electric motor—if the latter drives the drive shafts of both wheels by way of a series connection of a power divider or differential—, or two electric motors—if an independent motor is assigned to each vehicle wheel—, is/are fastened to the axle carrier, but also a so-called unit for providing electric power to the above-mentioned electric motor(s). Since a vehicle axle normally represents a preassembled unit which, in the manufacturing process of a vehicle, is first completed away from the vehicle body before the axle is fitted to the vehicle body, by use of an axle according to the invention, the essential elements required for the electric drive can not only be preassembled in a cohesive manner and can be tested with respect to their mutual interaction before the mounting on the vehicle body, but can also be cohesively connected with the vehicle body that is still preassembled separately. This leads to a particularly efficient manufacturing process. As far as the cohesive preassembling is concerned, particularly also the electric arrangement of the wiring between the above-mentioned unit for providing electric power and the electric motor or motors can be preassembled on an axle according to the invention, so that, during the joining with the vehicle body, no high-expenditure line installation (especially of lines carrying high electric currents) has to be carried out.
The above-mentioned unit for providing electric power can basically have various constructions. In the simplest case, this unit essentially consists of accumulators for storing electric power; in the most complex case, this unit may comprise a fuel cell with assigned accumulators. Here, the so-called electronic power system assigned to the accumulators is also a component of the above-mentioned unit and, if elements are required for temperature control, particularly the cooling of the accumulators and/or of the electronic power system, preferably these elements are also included in the “elements for providing electric power” as claimed herein.
Furthermore, it may be advantageous to arrange the above-mentioned elements for providing electric power inside a housing, and therefore in a manner protected from environmental influences by the housing. Naturally, this applies to only those elements for which such a protected arrangement makes sense. For example, a heat exchanger for cooling a heat transfer medium by ambient air, by which a temperature control of an element for providing electric power takes place, is not included in the above-mentioned elements. The above-indicated housing is fastened to at least one appropriately designed axle carrier basically known to a person skilled in the field of chassis design. However, it is particularly advantageous for this housing to virtually be a component of an axle carrier, on which the wheel-guiding control members or some of the members are fastened in a basically known manner. The above-mentioned housing is therefore structurally integrated in the axle carrier and may, thereby, form a so-called “base body” of the axle carrier, and advantageously, can be additionally functionally integrated in the axle carrier in that at least one of the wheel-guiding control members is linked to the above-mentioned housing or base body. Furthermore, similar to the known axle carriers, so-called arms (preferably four each) may be provided on the above-mentioned base body, the vehicle body being supported on end regions of the arms by way of rubber bearings.
Particularly advantageously, the above-mentioned housing can also contribute to the reduction of the drag coefficient of the vehicle; specifically, if the underfloor of the axle carrier facing the road with the above-mentioned housing is constructed to be essentially planar, which can be provided relatively easily with an appropriate housing wall.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.